Implantable medical devices (IMDs) can include implantable cardioverters or defibrillators, which can monitor for an arrhythmia and can deliver a high voltage shock to interrupt a fibrillating or tachyarrhythmic heart. This provides an opportunity for a normal heart rhythm to resume.
The high energy for the defibrillation or cardioversion shock can be generated in the IMD by using a flyback or other DC-to-DC voltage converter to upconvert a relatively low battery voltage (e.g., 3-6 Volts) to a high voltage (e.g., 300-800 Volts). The high voltage can be stored on a high voltage capacitor until shock delivery is desired. Then, a switch can be closed to deliver the defibrillation/cardioversion energy from the high voltage capacitor to electrodes located as desired in association with the subject to be defibrillated.